The contemporary Catholic Church has wholeheartedly
endorsed the ideas that Islam is a religion of peace and that Muslims
are the first victims of jihad terrorism.
This proposition is enforced as an iron dogma, the one non-negotiable
point in today’s comfortable suburban Church: anything goes, everything
is winked at, moral teaching is discarded or ignored left and right —
but whisper that Islamic jihadists point to the texts and teachings of
Islam to justify violence and supremacism, and you’ll be the new Jan
Hus.
A recent piece in the Los Angeles archdiocesan newspaper entitled “Our Muslim Brothers and Sisters”
is just one example of the endless barrage of nonsense that comes from
the U.S. Conference of Catholic Bishops on this issue — but this example
is noteworthy in being particularly counterfactual. It spends a great
deal of time admonishing us that the first victims of Islamic jihad
terror groups are other Muslims. Its author, Fr. Ronald Rolheiser,
apparently believes — along with Barack Obama and numerous other Western
leaders — that this proves that the Islamic State, al-Qaeda, and the
rest are un-Islamic.
In fact, this point only establishes that they believe their Muslim
opponents to be un-Islamic — and because Islam mandates death for heresy
and apostasy, they kill those opponents.
Rolheiser also says:

But the Muslim religion is not to blame here. There is
nothing inherent in either the Koran or in Islam itself that morally or
religiously undergirds this kind of violence.

Apparently Rolheiser has overlooked many passages from the Qur’an, including:

2:191-193: “And slay them wherever you
come upon them, and expel them from where they expelled you; persecution
is more grievous than slaying. But fight them not by the Holy Mosque
until they should fight you there; then, if they fight you, slay them —
such is the recompense of unbelievers, but if they give over, surely
Allah is All-forgiving, All-compassionate. Fight them, till there is no
persecution and the religion is Allah’s; then if they give over, there
shall be no enmity save for evildoers.”4:89: “They wish
that you should disbelieve as they disbelieve, and then you would be
equal; therefore take not to yourselves friends of them, until they
emigrate in the way of Allah; then, if they turn their backs, take them,
and slay them wherever you find them; take not to yourselves any one of
them as friend or helper.”5:33: “This is the recompense of those who fight
against Allah and His Messenger, and hasten about the earth, to do
corruption there: they shall be slaughtered, or crucified, or their
hands and feet shall alternately be struck off; or they shall be
banished from the land. That is a degradation for them in this world;
and in the world to come awaits them a mighty chastisement.”8:12: “When thy Lord was revealing to the angels, ‘I
am with you; so confirm the believers. I shall cast into the
unbelievers’ hearts terror; so smite above the necks, and smite every
finger of them!’”8:39: “Fight them, till there is no persecution and
the religion is Allah’s entirely; then if they give over, surely Allah
sees the things they do.”8:60: “Make ready for them whatever force and
strings of horses you can, to terrify thereby the enemy of Allah and
your enemy, and others besides them that you know not; Allah knows them.
And whatsoever you expend in the way of Allah shall be repaid you in
full; you will not be wronged.”9:5: “Then, when the sacred months are drawn away,
slay the idolaters wherever you find them, and take them, and confine
them, and lie in wait for them at every place of ambush. But if they
repent, and perform the prayer, and pay the alms, then let them go their
way; Allah is All-forgiving, All-compassionate.”9:29: “Fight those who believe not in Allah and the
Last Day and do not forbid what Allah and His Messenger have forbidden —
such men as practise not the religion of truth, being of those who have
been given the Book — until they pay the tribute out of hand and have
been humbled.”9:111: “Allah has bought from the believers their
selves and their possessions against the gift of Paradise; they fight in
the way of Allah; they kill, and are killed; that is a promise binding
upon Allah in the Torah, and the Gospel, and the Koran; and who fulfils
his covenant truer than Allah? So rejoice in the bargain you have made
with Him; that is the mighty triumph.”9:123: “O believers, fight the unbelievers who are
near to you; and let them find in you a harshness; and know that Allah
is with the godfearing.”47:4: “When you meet the unbelievers, smite their
necks, then, when you have made wide slaughter among them, tie fast the
bonds; then set them free, either by grace or ransom, till the war lays
down its loads. So it shall be; and if Allah had willed, He would have
avenged Himself upon them; but that He may try some of you by means of
others. And those who are slain in the way of Allah, He will not send
their works astray.”

Think the Bible is full of violence, too? Sure, but there is actually
nothing in the Bible remotely equivalent to the Qur’an’s open-ended and
universal commands to wage war against and subjugate unbelievers. Nor
will you find calls to violence being taught from authoritative sources
of Judeo-Christian religion.
But you will find them coming from the authoritative sources in Sunni Islam, the schools of Sunni jurisprudence (madhahib):

Shafi’i school: A Shafi’i
manual of Islamic law that was certified in 1991 by the clerics at
Al-Azhar University, one of the leading authorities in the Islamic
world, as a reliable guide to Sunni orthodoxy, stipulates about jihad
that “the caliph makes war upon Jews, Christians, and Zoroastrians …
until they become Muslim or pay the non-Muslim poll tax.” It adds a
comment by Sheikh Nuh Ali Salman, a Jordanian expert on Islamic
jurisprudence: the caliph wages this war only “provided that he has
first invited [Jews, Christians, and Zoroastrians] to enter Islam in
faith and practice, and if they will not, then invited them to enter the
social order of Islam by paying the non-Muslim poll tax (jizya) … while
remaining in their ancestral religions.” (‘Umdat al-Salik, o9.8).Hanafi school:
A Hanafi manual of Islamic law repeats the same injunctions. It insists
that people must be called to embrace Islam before being fought,
“because the Prophet so instructed his commanders, directing them to
call the infidels to the faith.” It emphasizes that jihad must not be
waged for economic gain, but solely for religious reasons: from the call
to Islam “the people will hence perceive that they are attacked for the
sake of religion, and not for the sake of taking their property, or
making slaves of their children, and on this consideration it is
possible that they may be induced to agree to the call, in order to save
themselves from the troubles of war.”
However, “if the infidels, upon receiving the call, neither consent
to it nor agree to pay capitation tax [jizya], it is then incumbent on
the Muslims to call upon God for assistance, and to make war upon them,
because God is the assistant of those who serve Him, and the destroyer
of His enemies, the infidels, and it is necessary to implore His aid
upon every occasion; the Prophet, moreover, commands us so to do.” (Al-Hidayah, II.140)Maliki school: Ibn Khaldun (1332-1406), a
pioneering historian and philosopher, was also a Maliki legal theorist.
In his renowned Muqaddimah, the first work of historical theory, he
notes that “in the Muslim community, the holy war is a religious duty,
because of the universalism of the Muslim mission and (the obligation
to) convert everybody to Islam either by persuasion or by force.” In
Islam, the person in charge of religious affairs is concerned with
“power politics,” because Islam is “under obligation to gain power over
other nations.”Hanbali school: The great medieval theorist
of what is commonly known today as radical or fundamentalist Islam, Ibn
Taymiyya (Taqi al-Din Ahmad Ibn Taymiyya, 1263-1328), was a Hanbali
jurist. He directed that “since lawful warfare is essentially jihad and
since its aim is that the religion is God’s entirely and God’s word is
uppermost, therefore according to all Muslims, those who stand in the
way of this aim must be fought.”

This is also taught by modern-day scholars of Islam.
Majid Khadduri was an Iraqi scholar of Islamic law of international renown. In his book War and Peace in the Law of Islam,
which was published in 1955 and remains one of the most lucid and
illuminating works on the subject, Khadduri says this about jihad:

The state which is regarded as the instrument for
universalizing a certain religion must perforce be an ever expanding
state. The Islamic state, whose principal function was to put God’s law
into practice, sought to establish Islam as the dominant reigning
ideology over the entire world. … The jihad was therefore employed as an
instrument for both the universalization of religion and the
establishment of an imperial world state. (P. 51)

Imran Ahsan Khan Nyazee, Assistant Professor on the Faculty of
Shari’ah and Law of the International Islamic University in Islamabad.
In his 1994 book The Methodology of Ijtihad, he quotes the twelfth century Maliki jurist Ibn Rushd:

Muslim jurists agreed that the purpose of fighting with
the People of the Book … is one of two things: it is either their
conversion to Islam or the payment of jizyah.

Nyazee concludes:

This leaves no doubt that the primary goal of the Muslim
community, in the eyes of its jurists, is to spread the word of Allah
through jihad, and the option of poll-tax [jizya] is to be exercised
only after subjugation [of non-Muslims].

Blissfully or willfully ignorant of all this and much more, Rolheiser says:

It’s time to establish a greater solidarity with Islam.

With Islam, mind you — not with Muslims who genuinely reject all this
and want to live in peace with non-Muslims as equals in a secular
society without trying to gain hegemony over them….